Slab handling device



0, 1968 c. o. TROWBRBDGE 3,397,992?

SLAB HANDLING DEVI CE 3 Sheets$heet 1 Filed Feb. 1, 1967 /A/VA/ roeCzar/exams D 7M5;

arrays-2s United States Patent 3,397,907 SLAB HANDLING DEVICE ClarenceDavid Trowbridge, Valparaiso, Inch, assignor to Inland Steel Company,Chicago, Ill., a corporation of Delaware Filed Feb. 1, 1967, Ser. No.613,280 Claims. (Cl. 294-81) ABSTRACT OF THE DISCLOSURE Disclosed is adevice for handling slabs of metal or other material. The deviceutilizes a pair of spaced apart lazy tongs characterized by elementswhich permit parallel movement of the tong jaws, and freedom fromstructural elements which protrude significantly beyond the width of thegripping jaws regardless of the distance at which they are apart. Thedevice permits the stacking of slabs into piles very close togethersince only a small distance between piles is required for the jaws tosatisfactorily grip and lift slabs from a pile.

BACKGROUND OF THE INVENTION (1) Field of the inventi0n.This inventionrelates to lifting devices. More particularly, it is concerned withdevices used for lifting slabs of material which are more or lessrectangular in shape, particularly metal slabs of steel.

(2) Description of the prior art.--In the manufacture of steel productsit is common for steel ingots to be processed into steel slabs which aresubsequently formed into various products such as steel plates and sheetmetal strip. Since steel slabs are not normally converted into otherproducts immediately after being formed, they are commonly stored in aslab yard. The steel slabs are generally placed one upon another intoconsecutive piles located in rows with each pile of slabs spaced apartfrom the next pile.

The amount of steel which can be stored in a slab yard will bedetermined to a considerable extent by the space between the slab piles.The closer the slab piles are placed to one another, the greater will bethe amount of steel that can be stored in any particular yard at onetime.

In the handling of steel slabs to and from a slab yard equipment must beemployed that can handle exteremely heavy loads, such as up to 125 tons,and handle slabs varying in width from about 1 /2 feet to over 6 feet.For this purpose, very rugged and strong lifting tongs have beenemployed in the past. Such lifting tongs have been used in a pair spacedapart by suitable spacers. Such tongs have been crescent shaped in amanner quite similar to the shape of tongs used for manually handlingblock ice. The arcuate shape of the tongs, plus the protruding linkagesused to operate the tongs, made it necessary for the slab piles to bespaced apart from 4 to 6 feet. Closer stacking of the slabs in piles waseither impossible or extremely impractical because of the clearanceneeded for the lifting tongs to properly fit between the piles and gripthe slabs to be moved.

SUMMARY OF THE INVENTION This invention provides a lifting device forslabs of metal, and other heavy materials, which permits stacking of theslabs into piles closely spaced together. The piles can be positionedclose together readily using the lifting device of this invention and,furthermore, the lifting device can be used subsequently for removingone or more of the slabs from such closely spaced slab piles.

The lifting device provided by this invention for handling metal slabsand the like comprises a pair of similar gripping members of the lazytong type connected in parallel spaced apart relationship from eachother by rigid spacers, each gripping member having two opposing jawsand jaw actuating means which moves the jaws in and out in parallelrelationship to one another, each jaw having a jaw body and an elongatedbar extending therefrom, a pair of intersecting lever arms pivotallyconnected to each other and pivotally connected at each lower end to ajaw body and at each upper end to the lower end of a pair of actuatinglinks with the upper ends of the actuating links being pivotally joinedtogether, guide means pivotally mounted on the gripping memberseparately receiving each elongated bar through a hole therein, andmeans operably associated with said actuating links to therebysimultaneously lift both gripping members whereby the weight of thelifting device and any load between the jaws forces the opposing jawsinwardly toward each other.

The lifting device is further charactetrized in one embodiment by havinga rigid spacer joining opposing gripping members at the intersectingpivot of the lever arms, and another spacer joining the opposinggripping members about at the connecting pivot of the upper ends of theactuating links. In addition, the pivot for the guide means, and thepivotal connection of the lever arms with the links are positioned so asto have a common axis. It is also advisable for each lever arm, and eachactuating link, to be made of at least two spaced apart bars of rods.

DESCRIPTION OF THE INVENTION IN CONJUNC- TION WITH THE ATTACHED DRAWINGSThe invention will now be discussed in conjunction with the attacheddrawings in which:

FIGURE 1 is an isometric view of one embodiment of the slab liftingdevice;

FIGURE 2 is a front elevational view of the slab lifting device ofFIGURE 1 with the jaws in an open nonlifting position;

FIGURE 3 is a front elevational view, similar to FIG- URE 2, but withthe jaws in a gripping and lifting position;

FIGURE 4 is a slightly enlarged view showing in greater detail the guidemeans through which the elongated bar attached to the jaw slides up anddown in the guide means during actuation of the lifting device;

FIGURE 5 is a vertical sectional View through the lower center part of ajaw;

FIGURE 6 is an isometric view of the jaw ends;

FIGURE 7 is an elevational view, partly in section through the pivotingmeans joining the links together;

FIGURE 8 is a plan view of the spacer separating the pairs of leverarms;

FIGURE 9 is a vertical sectional view along the line 9-9 of FIGURE 8;and

FIGURE 10 is a plan view, partially in section, of one end of the spacerwhich separates the pairs of actuating links.

In discussing the various elements of the drawings the same identifyingnumber will be used for the same part in the various figures so far asis practical.

The lifting device of FIGURES 1 to 3 has a pair of similar grippingmembers 10 and 11 which are generally described as of the lazy tong orlazy scissors type. The pair of gripping members 10 and 11 arepositioned opposite each other in parallel spaced apart relationship butare connected to one another by rigid spacers 12 and 13. Each grippingmember has two opposing jaws. The gripping member 10 has opposing jaws14 and 14A while gripping member 11 has opposing jaws 15 and 15A. Thejaws have openings to keep weight down. Each jaw has an elongated barextending upwardly therefrom. Jaw 14 has rod 16 while jaw 14A has rod16A; jaw 15 has rod 17 and jaw 15A has rod 17A.

Each gripping member 10 and 11 has a pair of intersecting lever armspivotally connected to each other intermediate their ends and pivotallyconnected at each lower end to a jaw body and at each upper end to thelower end of a pair of actuating links. Thus, gripping member has leverarm 18, composed of two rods 18A and 18B, pivotally connected at withlever arm 19, composed of rods 19A and 19B. Each lever, while showncomposed of two bars, can be made of a single bar if advisable. Thelever arms taper outwardly from each end and are widest in the vicinityof pivot 20 to provide necessary strength with minimum weight. 7

A pair of links 21 and 22 are connected at their lower ends in apivotable manner with the upper ends of the levers 18 and 19 such as bymeans of bolts .23 and 24. Each of the links 21 and 22 is shown composedof a. pair of rods or bars. Link 21 is shown made of rods 21A and 21Bwhile link 22 is made of rods 22A and 22B. Each link, while showncomposed of two bars, can be made of a single bar if advisable. Theupper ends of the links are pivotably connected by bolt 25.

The jaw body of each gripping member is shown pivotally connected to thelower ends of the lever arms. Gripping member 10 has jaw 14 pivotallyconnected to lever 18 by bolt 26 and jaw body 14A is pivotally connectedto lever 19 by bolt 27. Each elongated rod extending upwardly from thejaw body is supported in a slidable manner by a guide means so the jawsof the lifting device are maintained parallel as they move toward andaway from each other during movement of the device up and down.Elongated rod 16 extending from jaw 14 extends through a vertical holein guide means 28 which is shown positioned to pivot about an axiscommon to the pivot at the intersection of lever arm 19 and link 21.FIGURE 4 shows, in an enlarged sectional view, rod 16 slidably locatedin guide means 28. The rod 16 passes through hole 30 to provide slidableaction. Similarly, guide means 29 has a vertical hole in which rod 16Acan slide up and down, to maintain movement of jaw 14A in a pathparallel to jaw 14. Guide means 29 is also positioned to pivot about anaxis common to bolt 24 and this is effected by bolt 24 joining togetherguide means 29 and the ends of lever arm 18 and link 22.

Gripping member 11 is like gripping member 10 and thus will not bedescribed separately.

The face of each of the jaw bodies has a lower protruding lip, such aslip 35 on jaw body 14 and an elongated essentially vertical flat face 36as shown most clearly in FIGURE 5. The lip 35 on each of the jaw bodiesserves to firmly hold a slab being lifted by the device. In addition,the elongated flat face 36 maintains a group of slabs in a pile in aneatly positioned arrangement with respect to one another and serves tokeep them from shifting to one side or the other during lifting andtransporting, Lip 35 comprises in part a removable teeth carrying insert50 which has a protruding horizontal flange 51 at the rear which fitsinto a mating slot in the jaw face. A series of bolts 52 removably holdsthe insert in place. Teeth 53 serve to further grip slabs lifted by thedevice.

Rigid spacer 12 is positioned so that each of its ends is locatedessentially at the pivotal intersection of the lever arms, such as boltpivot 20 in gripping member 10. Spacer 12, as shown in FIGURES 8 and 9,is fabricated from two channel members 60 and 61 held fixedly apart bybraces 62 and end plates 63. At each end of the spacer 12 are positionedpivot bolts for holding the actuating members. Thus, bolt 20 is at oneend and holds actuating members 18 and 19. Collar 64 provides additionalsupport for bolt 20. A pair of bolts 66 pass through spacer 12 andprovide attachment means for cables 39 used to lift the whole liftingdevice when empty.

Each gripping member 10 and 11 has respectively a lifting eye 37 and 37Amounted pivotally to rotate on the same axis as the pivotal intersectionof the links, such as links 21 and 22 on member 10 which pivot on bolt25. Spacer 13 runs from lifting eyes 37 and 37A and serves, with spacer12, to maintain gripping members 10 and 11 in spaced apart parallelrelationship to one another. The spacers also restrict gripping members10 and 11 to simultaneous identical movement As shown in FIGURES 7 and10, spacer 13 is made of two channel members 70 and 71 held in fixedapart position by a block 72 at each end. Cables 39 pass between themembers 70 and 71.' Each lifting eye 37 and 37A is shaped like aninverted U with the legs of the U held rigid by a bar 73 which pivotsona'bolt such as 25.. j

Hook 42 serves to raise and lower the slab lifting device when it isempty. Cable 39' is purposely chosen to have only sufficient strength tosafely handle the empty lifting device. Cable 39 has insufiicientstrength to support both the weight of the lifting device and a steelslab to be transported in the jaws of the device. Since the jaws wouldnot have atight grip on a slab if lifting was tried by means of cable39, this action is defeated by breaking of the cable before the slab canbe moved. The actual lifting of a slab between the jaws of the liftingdevice is effected by means of heavy duty crane hooks placed in theopenings 45 and 46 in eyes 37 and 37A. Only when lifting is effectedthrough eyes 37 and 37A do the jaws of the device move together, inparallel arrangement, to grip a slab. The weight of the device in itselfinitially. causes the jaws to move together into gripping contact on .aslab as the eyes 37 and 37A are lifted by a suitable crane. The weightof the slab exerts further force which causes each pair of opposing jawsto be forced into even tighter gripping action on the slab.

With reference to FIGURE 2, the lifting device has been transported bybook 42 to be positioned over slab 50. After the lifting device has beenplaced in position over the slabto be transported, lifting force isapplied to eyes 37 and 37A thus causing the links and lever arms topivot about their connections and causing the jaws to move inwardly inparallel arrangement into contact with the slab. At this point cable 39is in a relaxed or slack posture and all lifting is done throughsuitable, hooking means placed through the eyes 37 and 37A.

- FIGURES l to 3 and FIGURE 5 show how the pro: truding lip 35 at theend of the jaws permit lifting of a plurality of slabs on a pile evenwhen upper slabs 81 are wider than the lowest slab 82 in the group beinglifted. This assures firm, secure gripping.

The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, as modifications will be obvious to those skilled in the art.

7 What is claimed is: a

1. A lifting device for metal slabs and the like comprising:

a pair of similar gripping members of the lazy tong type connected inparallel spaced apart relationship from each other by rigid spacers;each gripping member having two opposing jaws and I jaw actuating meanswhich moves the jaws in-and- I out in parallel relationship, to oneanother; each jaw having a jaw body and. an elongated bar eX- tendingtherefrom; a

a pair of intersection pivotally connected lever arms pivotallyconnected at each lower end to a jaw body and at each upper end to thelower end of a pair of actuating links, the upper ends of the actuatinglinks being pivotally joined together;

guide means, pivotally mounted, on the gripping member, separatelyreceiving each elongated bar through .a hole therein; and

means operably associated with said actuating links to therebysimultaneously lift both gripping members whereby the weight of thelifting device and any'load between the jaws forces opposing jawsinwardly toward each'other. j

'2. Alifti ng device according'to claimi in which a rigid spacer joinsthe-opposing gripping members at't'he inter-' the opposing grippingmembers at the connecting pivot of the upper ends of the actuatinglinks.

3. A lifting device according to claim 1 in which the pivot for theguide means, and the pivotal connection of the lever arms with thelinks, have a common axis.

4. A lifting device according to claim 1 in which each lever arm, andeach actuating link, comprises at least two spaced apart rods.

5. A lifting device for metal slabs and the like comprising:

a pair of similar gripping members of the lazy tong type connected inparallel spaced apart relationship from each other by rigid spacers;

each gripping member having two opposing jaws and jaw actuating meanswhich moves the jaws in-andout in parallel relationship to one another;

each jaw having a jaw body and an elongated bar extending therefrom;

a pair of intersecting pivotally connected lever arms pivotallyconnected at each lower end to a jaw body and at each upper end to thelower end of a pair of actuating links, the upper ends of the actuatinglinks being pivotally joined together;

each lever arm and each actuating link comprising at least two spacedapart rods;

one of said rigid spacers joining opposing gripping members at theintersecting pivot of the lever arms, and

another rigid spacer joining the Opposing gripping members at theconnecting pivot of the upper ends of the actuating links;

guide means mounted on the gripping member and pivoting about an axiscommon to the connecting pivot of the lever arm intersecting with theactuating links, said guide means separately receiving the elongated barextending from the jaw through a hole therein; and

means operably associated with said actuating links to therebysimultaneously lift both gripping members whereby the weight of thelifting device and any load between the jaws forces opposing jawsinwardly toward each other.

References Cited UNITED STATES PATENTS 905,010 11/ 1908 Simmons.2,382,227 8/1945 Hopkins et a1. 294119 X 2,784,923 3/1957 Sepke 2941 13X 3,154,339 10/1964 Kaplan 294-113 X 3,359,033 12/1967 Curtis 294-119 XRICHARD E. AEGERTER, Primary Examiner.

M. L. AJEMAN, Assistant Examiner.

